Ramos David, Pellín-Carcelén Ana, Agustí Jaime, Murgui Amelia, Jordá Esperanza, Pellín Antonio, Monteagudo Carlos
Department of Pathology, University of Valencia, Valencia, Spain
Department of Pathology, University of Valencia, Valencia, Spain.
Anticancer Res. 2015 Jan;35(1):439-44.
BACKGROUND/AIM: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a highly abundant housekeeping gene. GAPDH overexpression has been reported in diverse types of human cancers including cutaneous melanoma. Our goal was to quantify GAPDH mRNA and protein expression in the whole spectrum of primary and metastatic melanomas in the search for a specific role for this ubiquitous molecule during tumor progression.
Intratumoral GAPDH mRNA expression was quantified by real-time PCR in 71 cases, including 29 primary melanomas and 42 metastatic cases. Relative expression levels in thin (≤1 mm) and thick (>1 mm) primary tumors and 'in-transit', lymph node and distant metastases were compared. Similarly, protein expression was investigated by means of immunohistochemistry. Specific exons of GAPDH were analyzed by DNA sequencing.
GAPDH mRNA expression was significantly up-regulated in thick melanomas when compared to primary thin melanomas. Similar differences were also encountered between metastatic melanomas when compared to lymph-node metastatic melanomas. Interestingly, GAPDH protein immunoexpression was higher in thick melanomas and distant metastases than in thin tumors and lymph node metastases, respectively. However, no specific point-mutations in GAPDH-specific exons were found in any patient.
Deregulation of GAPDH during melanoma progression was demonstrated in our series by mRNA and protein expression studies.
背景/目的：甘油醛-3-磷酸脱氢酶（GAPDH）是一种高度丰富的管家基因。据报道，GAPDH在包括皮肤黑色素瘤在内的多种人类癌症中均有过表达。我们的目标是量化原发性和转移性黑色素瘤全谱中GAPDH的mRNA和蛋白质表达，以寻找这种普遍存在的分子在肿瘤进展过程中的特定作用。
通过实时PCR对71例患者肿瘤内的GAPDH mRNA表达进行定量分析，其中包括29例原发性黑色素瘤和42例转移病例。比较了薄型（≤1 mm）和厚型（>1 mm）原发性肿瘤以及“途中”转移、淋巴结转移和远处转移中的相对表达水平。同样，通过免疫组织化学研究蛋白质表达。通过DNA测序分析GAPDH的特定外显子。
与原发性薄型黑色素瘤相比，厚型黑色素瘤中GAPDH mRNA表达显著上调。与淋巴结转移性黑色素瘤相比，转移性黑色素瘤之间也存在类似差异。有趣的是，GAPDH蛋白免疫表达在厚型黑色素瘤和远处转移中分别高于薄型肿瘤和淋巴结转移。然而，在任何患者中均未发现GAPDH特定外显子的特定点突变。
通过mRNA和蛋白质表达研究，我们的系列研究证明了黑色素瘤进展过程中GAPDH的失调。
